Add error propagation into Unwinder/Elf objects.

The backtrace offline code uses these error codes to diagnose errors.
In addtion, I've had cases where seeing these errors would help diagnose
failures.

This also allows us to add a few features to indicate why an unwind
terminated (such as max frames exceeded).

Bug: 65682279

Test: Updated unit tests pass.
Change-Id: If82b5092698e8a194016d670efff1320f9b44d50
diff --git a/libunwindstack/tests/DwarfCfaTest.cpp b/libunwindstack/tests/DwarfCfaTest.cpp
index 73a67ac..68dc30c 100644
--- a/libunwindstack/tests/DwarfCfaTest.cpp
+++ b/libunwindstack/tests/DwarfCfaTest.cpp
@@ -21,13 +21,13 @@
 
 #include <gtest/gtest.h>
 
+#include <unwindstack/DwarfError.h>
 #include <unwindstack/DwarfLocation.h>
 #include <unwindstack/DwarfMemory.h>
 #include <unwindstack/DwarfStructs.h>
 #include <unwindstack/Log.h>
 
 #include "DwarfCfa.h"
-#include "DwarfError.h"
 
 #include "LogFake.h"
 #include "MemoryFake.h"
@@ -78,7 +78,7 @@
     dwarf_loc_regs_t loc_regs;
 
     ASSERT_FALSE(this->cfa_->GetLocationInfo(this->fde_.pc_start, 0x2000, 0x2001, &loc_regs));
-    ASSERT_EQ(DWARF_ERROR_ILLEGAL_VALUE, this->cfa_->last_error());
+    ASSERT_EQ(DWARF_ERROR_ILLEGAL_VALUE, this->cfa_->LastErrorCode());
     ASSERT_EQ(0x2001U, this->dmem_->cur_offset());
 
     ASSERT_EQ("", GetFakeLogPrint());
@@ -198,7 +198,7 @@
   dwarf_loc_regs_t loc_regs;
 
   ASSERT_FALSE(this->cfa_->GetLocationInfo(this->fde_.pc_start, 0x2000, 0x2001, &loc_regs));
-  ASSERT_EQ(DWARF_ERROR_ILLEGAL_STATE, this->cfa_->last_error());
+  ASSERT_EQ(DWARF_ERROR_ILLEGAL_STATE, this->cfa_->LastErrorCode());
   ASSERT_EQ(0x2001U, this->dmem_->cur_offset());
   ASSERT_EQ(0U, loc_regs.size());
 
@@ -227,7 +227,7 @@
   dwarf_loc_regs_t loc_regs;
 
   ASSERT_FALSE(this->cfa_->GetLocationInfo(this->fde_.pc_start, 0x4000, 0x4002, &loc_regs));
-  ASSERT_EQ(DWARF_ERROR_ILLEGAL_STATE, this->cfa_->last_error());
+  ASSERT_EQ(DWARF_ERROR_ILLEGAL_STATE, this->cfa_->LastErrorCode());
   ASSERT_EQ(0x4002U, this->dmem_->cur_offset());
   ASSERT_EQ(0U, loc_regs.size());
 
@@ -594,7 +594,7 @@
   // This fails because the cfa is not defined as a register.
   ASSERT_FALSE(this->cfa_->GetLocationInfo(this->fde_.pc_start, 0x100, 0x102, &loc_regs));
   ASSERT_EQ(0U, loc_regs.size());
-  ASSERT_EQ(DWARF_ERROR_ILLEGAL_STATE, this->cfa_->last_error());
+  ASSERT_EQ(DWARF_ERROR_ILLEGAL_STATE, this->cfa_->LastErrorCode());
 
   ASSERT_EQ("4 unwind Attempt to set new register, but cfa is not already set to a register.\n",
             GetFakeLogPrint());
@@ -637,7 +637,7 @@
   // This fails because the cfa is not defined as a register.
   ASSERT_FALSE(this->cfa_->GetLocationInfo(this->fde_.pc_start, 0x100, 0x102, &loc_regs));
   ASSERT_EQ(0U, loc_regs.size());
-  ASSERT_EQ(DWARF_ERROR_ILLEGAL_STATE, this->cfa_->last_error());
+  ASSERT_EQ(DWARF_ERROR_ILLEGAL_STATE, this->cfa_->LastErrorCode());
 
   ASSERT_EQ("4 unwind Attempt to set offset, but cfa is not set to a register.\n",
             GetFakeLogPrint());
@@ -679,7 +679,7 @@
 
   // This fails because the cfa is not defined as a register.
   ASSERT_FALSE(this->cfa_->GetLocationInfo(this->fde_.pc_start, 0x100, 0x102, &loc_regs));
-  ASSERT_EQ(DWARF_ERROR_ILLEGAL_STATE, this->cfa_->last_error());
+  ASSERT_EQ(DWARF_ERROR_ILLEGAL_STATE, this->cfa_->LastErrorCode());
 
   ASSERT_EQ("4 unwind Attempt to set offset, but cfa is not set to a register.\n",
             GetFakeLogPrint());